This invention relates to an improved electronic infusion device which causes the roller clamp of an intravenous administration set to interact with the device in such a way that dangerous, accidents gravity free flow will not occur. More specifically, the invention requires loading of the roller clamp into the infusion device and prevents removal of the IV set from the infusion device until the roller clamp is closed. This prevents fluid flow when the IV set is removed from the infusion device. It also enables a standard gravity IV set to become a "protected" set without the addition of any special components to the set.
By way of Definition
ELECTRONIC INFUSION DEVICES (EID), which are also known as infusion pumps or infusion controllers, are used accurately to regulate the flow rate of intravenous fluids and to electronically monitor and alarm should a variety of unsafe occurrences be detected relating to the infusion.
INTRAVENOUS (IV) SETS, also called IV sets or gravity sets, are single use, disposable, sterile, tubing sets that connect the IV fluid container (a bag or bottle) with the patients's catheter. IV sets are used either with EID's or n their own when the relatively inaccurate flow rates they are capable of providing are clinically acceptable.
ROLLER CLAMPS are components found on IV sets. They consist of an operator adjusted roller wheel mounted in a small plastic housing. The roller wheel pinches the IV tubing to varying degrees ranging from fully closed to partially open (which results in controlled gravity flow), to fully open When an IV set is loaded n an EID the roller is left fully open to allow the EID to control flow rate.
FREE FLOW occurs whenever an IV set is not in an EID and its roller clamp (and all other IV set clamps) are fully open. While there are a few clinical conditions where free flow is desirable, in most cases free flow refers to an accidental and dangerous condition that can lead to patient injury or death. These accidental free flow conditions most commonly occur when IV sets are removed from EID's without the operator remembering to close the sets roller clamp first.
PROTECTED IV SETS, as defined by ECR1 are either; dedicated infusion pump sets that include a special IV set component which interacts with the EID when the set is unloaded to prevent gravity free flow, or they are standard gravity IV sets whose roller clamps must be closed before the EID allows set removal. FNT .sup.1 ECRI, Emergency Care Research Institute, is a non-profit organization that evaluates and reports on medical instrumentation to the health care industry.
Some prior art EIDs (such as the trademark VAC 500 and which used standard gravity IV sets employed doors to keep the tubing closed, preventing free flow while the tubing was held in the device. However, if the device's door was opened before the sets'roller clamp was closed, free-flow occurred. Other prior art EIDs (such as the SIGMA 5000) were equipped with both a door and a "flow stop". If the door was opened with an open roller clamp the spring activated flow stop would close the IV tubing to prevent free flow. This two step process to initiate gravity flow was considered the industry standard for preventing Free flow and still is the AAMI (American Association of Medical Instrumentation) standard.
However, due to the rising importance of preventing accidental free flow, ECRI (Emergency Care Research Insitute) has created a "quasi" standard. It states that in order to assure free-flow protection, either anti-free flow infusion sets ("protected sets") should be used with EIDs (an example being med's trademark Gemini V pump referenced in U.S. Pat. 2,689,043) or the EID design should force the operator to close the IV set's roller clamp prior to removing the set from the device.
The primary object of this invention is to provide an EID design that interacts with the roller clamp of a standard IV set in such a way that the clamp is always closed prior to removal of the set from the EID, thus preventing accidental free flow.
Still another objective is to be able to remove the EID's modular roller clamp holder so that it can be replaced with new roller clamp holders able to accommodate roller clamps of varying dimension. In this manner, the EID is compatible with the IV sets and roller clamps of multiple manufacturers.
Other objectives of this invention will be apparent hereinafter from the specification and from recital of the appended claims, particularly when read with the accompanying drawings.